The present invention relates to a safety infusion needle assembly and more particularly to an infusion needle assembly whose needle is automatically retractable into the housing of the needle assembly after use for preventing the contaminated needle from further exposure.
There are a number of retractable butterfly needle assemblies. U.S. Pat. No. 5,514,971 discloses a butterfly needle assembly whose needle is manually retracted into the housing. A retaining pin that biases against the body of the needle springs down when the needle clears it to prevent the retracted needle from further usage.
U.S. Pat. No. 5,746,215 discloses an IV needle assembly that has a needle that is automatically retractable. For the device of the ""215 patent, a complicated system that includes rear and forward locking tabs at the needle hub coact with locking ribs at the needle housing for maintaining the needle at its extended or retracted position. To retract the needle into the housing using a tensioned spring, an extended bridge with two opposite portions has to be compressed by the user and be flattened.
U.S. Pat. No. 5,779,679 discloses a winged IV needle assembly that includes a pair of additional wings fitted with appropriate tabs for coacting against contact lugs at the needle hub for retracting the needle hub and its attached needle into the housing.
U.S. Pat. No. 5,968,016 discloses a winged needle device that requires the user to pull the wings in opposite direction to each other in order to deform the latches that hold the catch of the needle in place, so that the needle is retracted into the housing by a tensioned elastic tube.
U.S. Pat. No. 6,210,371 discloses a device that is similar to the ""679 device in that an additional pair of wings, with the appropriate contact and tabs, is used for releasing the catch portion of the needle from catches at the housing to retract the needle into the housing.
The present invention winged needle device aims to improve upon the above-noted prior art devices, both in terms of simplicity in construction and use.
To protect against accidental pricking, the contaminated needle of an IV or butterfly needle device is designed with an automatic retracting mechanism that is activated when the user pushes a button, or key, in a given direction. Once the mechanism is pushed or actuated, the needle is automatically retracted into the housing, and remains confined within the housing.
To achieve this end, the housing of the needle device of the instant invention is formed with a passage that communicates with the bore of the housing. The passage may be in the form of an upraised well, at either the front end or the rear portion of the housing. Alternatively, the passage may be in the form of a sleeve orthogonal to the housing. For the well passage embodiment, a push mechanism in the form of a push button is fitted into the well. The button is in the form of a base that has extending therefrom two legs into the well. The inside opposing portions of the two legs converge at their distal ends so that the opening formed by the two legs is non-uniform, as the space or aperture defined by the inner opposing walls of the two legs that are not converged towards each other has a dimension that is greater than the space defined by the converging inner portions of the two legs. The well is formed on the housing such that, when the push mechanism is inserted thereinto, the different dimensioned spaces or apertures formed by the two legs would selectively intersect the bore of the housing, as the button and more specifically the space defined by the two legs of the button is in a transverse, or orthogonal, relationship to the longitudinal axis of the housing.
On the outside wall of each of the legs of the push button there are formed at least two one-way notches that coact with a corresponding catch extending from the inside wall of the well. The notches are formed at appropriate locations along the legs so that different placement locations are defined for the push button, relative to the housing. For the exemplar embodiments, such placement locations represent a first position whereat the space defined by the converged inner portions of the two legs intersects the bore of the housing. The second placement location is defined when the push button is further positioned toward the housing so that the space defined by the inner non-converging portions of the two legs intersects the bore of the housing.
A needle assembly that has a needle hub and a needle extending therefrom is slidably fitted within the bore of the housing. The needle hub has a collar or a rib at a portion thereof that coacts with or abuts against a bias element in the housing such as for example a tensioned spring or elastic tube. While the one side of the collar is being biased by the tensioned bias element, the other side of the collar is abutted by the converged legs of the push button so that the needle extending from the needle hub continues to extend out of the housing for use with a patient at the first placement location of the push button.
After use, the push button is moved closer relative to the housing so that, in the case that it is fitted to a well upraised from the housing, the top of the push button becomes flush with the top rim of the well. At that point, the space defined by the non-converging portions of the legs extending from the button intersects the bore of the housing such that the collar about the needle hub would pass through the space due to the biasing force exerted by the bias element. Consequently, as the needle hub is biased toward the end of the housing, the needle that extends from the needle hub is retracted within the housing. A stopper at the end of the housing maintains the front portion of the needle hub within the housing, as the collar abuts the stopper. The contaminated needle is therefore retained within the housing.
To prevent the push button from being inadvertently pushed down, particularly when the needle is inserted into a patient, a safety lock, in the form of a safety button or plug, is fitted to a cavity of the push button. While the push button is at its first placement location, the space defined by the converged portions of its legs intersects the bore of the housing. The safety lock is ordinarily biased away from the cavity of the push button so that it prevents the push button from being pushed into the well. It is only after the needle has been withdrawn from the patient and the safety lock pushed into the cavity of the push button that the push button may be pushed into the well to its second placement location where the space defined by the non-converging portions of its legs intersects the bore of the housing. Coacting mechanisms in the form of notches at the legs and catches at the inner wall of the well maintain the push button at the respective first and second placement locations.
A second embodiment of the instant invention needle device utilizes a push button that, in addition to being able to be selectively positioned at first and second placement locations, also has flaps that prevent the needle hub from completely passing out of the housing, once the push button is pressed to its placement location that allows retraction of the needle into the housing. For this embodiment, the push button may be located at the end portion of the housing.
Yet another embodiment of the instant invention needle device integrates a sleeve at the distal portion of the housing. A key is inserted to the sleeve and is movable to at least a first and second placement location orthogonal to the longitudinal axis of the housing. The key is formed with a non-uniform opening, with differently dimensioned apertures, one of which would prevent the movement of the needle hub, while the other would allow the needle hub to pass through for retracting the needle into the housing. Coacting teeth at the sleeve and key maintain the placement of the key until the user manually pushes the key. Further, the teeth at the key are one-way teeth, so that once pushed to the placement location enabling the retraction of the needle, the key could no longer be repositioned to its first placement location.